The present invention pertains to a novel horizontal well bore system which can be used to drill and develop ground water monitoring and remediation wells, and to place horizontal drains for capturing contaminant particles beneath difficult areas such as landfills, lagoons, and storage tanks.
A large variety of horizontal well bore systems have been developed and used in the past. Generally, these systems begin with a vertical hole or well. At a certain point in this vertical well, a turn of the drilling tool is initiated which eventually brings the drilling tool into a horizontal position thereby allowing the drilling of a horizontal or lateral well. In the past, horizontal/lateral wells have generally been used for draining large areas or as collector radials for large diameter wells.
When oil and gas recovery became more important, horizontal wells were used to access irregular fossil energy deposits in order to enhance such recovery. Furthermore, horizontal drilling techniques have also been used for placing underground conduit systems beneath obstacles such as lakes, rivers, and other at and below-ground-level obstructions.
Even more recently, horizontal wells and the lateral drilling technology used to form the same have been applied in the field of pollution control. More particularly, horizontal wells can be placed beneath landfills, hazardous waste sites, or potentially or actually leaking underground storage tanks in order to monitor the migration of a hazardous substance and to prevent the hazardous substance from reaching the ground water. Horizontal wells can also be used for remediation purposes.
For example, U.S. Pat. No. 4,832,122 to Cory, et al., discloses an in-situ remediation system for contaminated ground water which discloses the use of two horizontal wells, one positioned below the plume in the saturated zone and one above the plume in the vadose zone. A fluid is injected through the lower horizontal well into the saturated zone and, after reacting with the contaminant, is removed by the upper level extracting well for further treatment. See also, "Radial Wells and Hazardous Waste Sites", W. Dickinson, et al., RCRA SITE REMEDIATION, pp. 232-237.
Unfortunately, the prior art horizontal drilling technology has not been fully successful, especially for use with the remediation and monitoring of hazardous substances. Even though lateral drilling technology for drilling short, medium, and long-radius lateral bore holes is available (see, e.g., "Lateral Drilling Technology Tested On UCG Project", P. B. Tracy, IADC/SPE Paper No. 17237, pp 493-502 (1988)), new and special techniques are needed to overcome the problematic application of lateral drilling technology to environmental problems.
More particularly, horizontal drilling systems for use with environmentally sensitive applications need to be extremely accurate, both in initial drilling accuracy and later monitoring accuracy, they need to be portable, maneuverable, and fast, and they need to drill and form a horizontal well which will maintain its integrity in a variety of corrosive and damaging environments. Furthermore, horizontal drilling systems must be cost-effective in order to meet the requirements of today's cost conscious communities and their governments.